SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aca51957199ebab904590ce0a7d12e0094ed5cdac13fedd1777502be3a4300d5' 
  AND token = 'ucoRbTRbIbi3siNwy4aUZnAKtqfYaOaDbOTR0S5KtNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}